How are bones made?
LIVING WORLD: Liam Monaghan, who is aged 10 and a student at Waikanae School, asked this question.
Bones you see in a skeleton in a museum look dry and hard and you might think that all bones are dead. But the bones that make up your skeleton are all very much alive, growing and changing all the time like other parts of your body.
The outer surface of bone contains nerves and blood vessels that nourish the bone. The next layer is made up of compact bone. This part is smooth and very hard. It's the part you see when you look at a skeleton.
Within the compact bone is another layer which looks a bit like a sponge. This protects the innermost part of the bone, the bone marrow. Bone marrow is sort of like a thick jelly, and its job is to make blood cells.
Professor John Montgomery answered this question. He is a Fellow of Royal Society Te Apārangi, which means he’s one of the top experts in his field of life sciences and especially marine biology. John works at The University of Auckland.
View his profile: Professor John Montgomery